Sheets of glass, either in simple sheet form or in more complex forms, are particularly subject to damage during shipping. In addition, because of the nature of glass manufacturing operations and the economies of scale attendant continuous production, sheet glass, once cut to size and/or formed into special items [such as insulating, sealed double (or more) panes] to be used in insulating glass windows, often must be warehoused in inventory. The amount and expense of warehouse space required would be prohibitive if the glass sheets could not be packaged in containers and stacked two or more containers high.
In order to accommodate these needs, the glass manufacturing industry has devised numerous types of stackable containers. Generally speaking, the most popular of these containers employ wooden or metal decks, called pallets, to which are attached two or more fence-like vertical walls of wood or metal. Glass sheets placed in these containers are shorter than the walls, so that when one container is stacked upon another, the container's walls become the load-bearing members in the stacked system. While such containers were at times wrapped in cardboard, and/or metal straps or large widths of fiberglass reinforcing tape for better lateral integrity, the weight and expense of providing the heretofore believed necessary metal or wooden fence-like vertical load-bearing walls was less than desirable. In addition, such containers were difficult to disassemble and were often rendered unusable, even in part, by the end user (e.g. the fabricator of the final product from the glass sheets) through disassembly. If partially reusable, it was usually only reusable by the first user, i.e. the glass manufacturer, thus necessitating the costs attendant having to ship back the reusable part (e.g. the pallet deck), along with the care required in disassembly to make sure it would be reusable. In all of these early designs it was usually considered detrimental or not feasible to use the glass sheets as a partial load-bearing member during stacking.
In an earlier design by the subject inventor and others at the inventor's assignee company, a structure was devised which eliminated the need for heavy, upstanding, fence-like walls of wooden boards or metal pipes. This container employed multiple walls of very heavy (e.g. 1500-1800 lb. test) corrugated cardboard, such that one wall formed a tube within a tube with regard to the other walls . . . usually a total of three in number. By using appropriate creasing and underflaps for attachment to the wooden pallet, all four sides of the container were provided with a multiwalled corrugated cardboard structure having four underflaps (one for each side, including the front wall). With lateral stability provided by the glass sheets, the container walls, a "cap" top and wraparound metal strips, the container was strong enough to be stacked up to four or more containers high. Like past containers, however, the walls of the container were designed to extend above the glass sheets so as to insure that during stacking the glass sheets would bear none of the vertical loads caused by the stacking.
This latter design, while a significant technical improvement in the art, turned out to be less than fully successful, primarily for certain significant practical reasons. First, the cardboard employed was very heavy and rather expensive. Secondly, assembly of a tri-walled structure employing two inner walls was somewhat arduous. Thirdly, and perhaps most importantly, was the fact that it was rather difficult to disassemble from the final user's perspective, who had to first remove the front face of the container, while leaving the rest of the sides intact so he could unload the glass sheets from the container.
In view of the above, it is apparent that there exists a need in the art for a container for sheets of glass which is stackable, and yet which overcomes the above problems attendant prior containers. It is a purpose of this invention to fulfill this and other needs in the art, which will become more apparent to the skilled artisan once given the following disclosure: